Brake, method for determining its state, traction machine and elevator system

Abstract

A brake, a method for judging its state, a traction machine, and an elevator system. The traction machine and the elevator system include the brake. The brake includes a moving plate, and a fixed element having a fixed position relative to a base of the brake, and the brake further includes a first solenoid coil and a first ferromagnetic body; the first solenoid coil is disposed on one of the moving plate and the fixed element, the first ferromagnetic body is disposed on the other of the moving plate and the fixed element, a relative position of the first solenoid coil and the first ferromagnetic body is set such that the inductance of the first solenoid coil can change with the distance between the moving plate and the fixed element.

What is claimed is: 
     
         1 . A traction machine brake, wherein the brake comprises a moving plate, and a fixed element having a fixed position relative to a base of the brake, and the brake further comprises a first solenoid coil and a first ferromagnetic body,
 wherein the first solenoid coil is disposed on one of the moving plate and the fixed element, the first ferromagnetic body is disposed on the other of the moving plate and the fixed element, a relative position of the first solenoid coil and the first ferromagnetic body is set such that the inductance of the first solenoid coil can change with the distance between the moving plate and the fixed element.   
     
     
         2 . The brake according to  claim 1 , wherein the brake further comprises a detection and control circuit which has a detection element and a controller, and the controller determines a locked or unlocked state of the brake based on an output current and/or inductance of the first solenoid coil detected by the detection element. 
     
     
         3 . The brake according to  claim 1 , wherein the first solenoid coil is formed on a bracket or a pillar extending from the fixed element. 
     
     
         4 . The brake according to  claim 1 , wherein the fixed element is the base of the brake or is integrally formed with the base. 
     
     
         5 . The brake according to  claim 1 , wherein the fixed element is a static plate of the brake. 
     
     
         6 . The brake according to  claim 5 , wherein the brake further comprises a friction plate for braking the traction machine, the static plate and the friction plate are spaced apart, and the static plate has a second solenoid coil,
 the moving plate is located between the friction plate and the static plate, wherein when the brake is locked, the moving plate moves toward the friction plate under the action of a resetting force and causes the friction plate to brake the traction machine, and when the brake is unlocked, the moving plate overcomes the resetting force under the action of an electromagnetic force of the second solenoid coil and moves toward the static plate.   
     
     
         7 . The brake according to  claim 6 , wherein the position where the first solenoid coil is disposed avoids a magnetic circuit of the second solenoid coil. 
     
     
         8 . The brake according to  claim 5 , wherein the first solenoid coil is disposed on an outer peripheral side of the static plate; or the first solenoid coil is disposed at the center of the static plate; or the first solenoid coil is embedded in the static plate. 
     
     
         9 . The brake according to  claim 5 , wherein the static plate and the friction plate are spaced apart in a radial direction of an output shaft of the traction machine. 
     
     
         10 . The brake according to  claim 5 , wherein the static plate and the friction plate are spaced apart in an axial direction of an output shaft of the traction machine. 
     
     
         11 . The brake according to  claim 10 , wherein the number and/or position of the first solenoid coil coincides with a functional element at the static plate in an axial direction of the static plate. 
     
     
         12 . The brake according to  claim 11 , wherein the functional element is at least one of an encoder, a resetting device that generates the resetting force, a guide sleeve, a washer, and a screw. 
     
     
         13 . A method for judging the state of the brake according to  claim 1 , wherein the method comprises the following steps:
 inputting a sinusoidal wave voltage into the first solenoid coil;   measuring a current and/or inductance of the first solenoid coil; and   determining the state of the brake based on a change in the measured current and/or inductance.   
     
     
         14 . A traction machine for an elevator system, comprising the brake according to  claim 1 . 
     
     
         15 . An elevator system, comprising the traction machine according to  claim 14 .